Beverages, such as teas, containing caffeine are consumed throughout the world. The extraction of tea material is known in the art. For example, U.S. Pat. No. 5,427,806 discloses a process for the production of green tea extracts using a gelatin solution to remove oxidized or polymerized flavanols. However, this process uses an acidified aqueous solution containing preservatives to obtain the green tea extract from the green tea materials. A later patent by the same group, U.S. Pat. No. 5,780,086 discloses color and shelf stable beverage compositions containing tea extracts including a beverage syrup for use in juices, carbonated and non-carbonated beverages. However, the tea product claimed contains green tea extracts obtained by contacting the green tea materials with an acidified solution containing preservatives, which is subsequently gelatin treated, clarified and concentrated. In addition, this patent also contemplates the addition of synthetic compounds, such as caffeine, to the beverage compositions. A tea extract and process is also disclosed in United States statutory invention registration number H1,628. The process there describes extraction of tea materials with water, mixing the extract containing solution with protein, acidifying the protein containing extract and separating the precipitate. One of the preferred proteins listed is gelatin of any particle size derived from animal protein. Furthermore, compositions including the use of synthetic compounds such as caffeine are described. A recently published US patent application 20050186314, discloses the use of silica or silica-containing compounds to remove proteins and polysaccharides from green tea extracts in beverages that are sold hot. The application describes extraction of green tea leaves with hot water prior to silica treatment and contemplates the addition of acid after the extraction procedure.
Recent US patent applications have been published describing the use of hex species in formulations, as either the main component or part of the formulation, for human therapeutic purposes. The genus llex is found worldwide in subtropical and tropical regions. I. paraguariensis is known as maté and is the most commercialized plant of South America. US patent applications 20050118293 and 20050089591 describe compositions derived from llex species, particularly llex paraguariensis, having lowered caffeine and tannin concentrations, as oral delivery formulations for use in the treatment of human physiological and medical conditions. However, the application claims an extraction process from native maté plant material using supercritical carbon dioxide solutions under pressure. The application also describes mate compositions having predetermined characteristics, such as a lowered amount of caffeine, elevated amounts of caffeoyls, and/or lowered amounts of tannin compounds compared to the native maté plant materials. However, the specification notes that some of the chemical constituents found in maté, such as caffeine, theobromine and theophylline may be purchased from a chemical supply company. In US patent application 20050089584, a method and composition for oral delivery of Areca and maté or theobromine for use in the treatment of mental and physical conditions is disclosed. In US patent application 20050037025, a method and compositions comprising kava and maté or theobromine for the treatment of conditions related to mental and physical fatigue is claimed. Extraction methods disclosed in both these applications include steam distillation, liquid extraction (using dicholoromethane or petroleum ether), hydroalcoholic extraction, Soxhlet extraction and supercritical carbon dioxide solution under pressure. The specification from both of these patent applications also notes that theobromine may be obtained from maté, other sources or made by synthetic means known to those skilled in the art.
Prior efforts to make a maté syrup for use in maté beverages are disclosed in German patent number 1106154 issued in 1959. The German patented process employs an aqueous extraction of maté leaf using boiling water under pressure. The tea brew extract is then treated with preservatives such as sodium benzoate (0.08%) and a high concentration of citric acid (6.5%). The extract is then stored for 14 days, treated with a silica compound and filtered through an asbestos filter. However, the product from the patented German process is not certified organic, relies on a high degree of acidity and on the addition of chemical preservatives to achieve a functional shelf-life. In addition, caffeine levels in the German product are achieved through the addition of synthetic caffeine, rather than utilizing caffeine derived solely from the maté plant.
Therefore there is a need in the art for a process of preparing a maté extract rich in natural caffeine, theobromine, theophylline and antioxidant compounds completely derived from maté plant materials, without the addition of preservatives and synthetic materials/compounds for use in the preparation of a preservative-free maté beverage base formulation.